Umbrella anchor



Feb. 17, 1959 D. WIEGMANN 2,373,829

UMBRELLA ANCHOR Filed March 24, 1955 5 Sheets5heet 2 4 INVENTOR.

DIE O WEIG ANN ATTORNEY Feb. 17, 1959 Fild March 24, 1955 D. WIEGMANN2,873,829

UMBRELLA ANCHOR 3 Sheets-Sheet 3 MMIIIIHI INVENTOR.

. DlETRI H WEIGMANN ATTORNEY UMBRELLA ANCHOR Dietrich Wiegmaun, Bremen,Germany, assignor of onehalf to Paul Tobeler, doing business asTrans-Oceanic, Los Angeles, Calif. J

Application Marc 24, 1955, Serial No. 496,548

' "6 Claims. cuss-92 This invention relates generally tosubterraneananchors for supporting walls, piles and the like, and more specificallyhas to do with umbrella anchors having armsadapted to be expandedunderground to provide tension or bearing supports for correspondingloads. The invention especially concerns itself with a novel type anchoradapted to be introduced undergroundin a casing and subsequentlymanipulated from a remote point after removalof the casing to accomplishexpansion of the an-.

chor arms into the surrounding subterranean material.

' In previous devices ofthis -so'rt,the anchor arms have,

in certain cases been connected to supporting structure in such a waythat expansion of the arms was sought to be accomplished by displacingthe support structure with cement or other material introduced in thehole, the weight of the cement being depended upon to expand the armsoutward into the soil. In other cases the protective casing. was left inthe ground and the anchor arms were forced out throughslits in thecasingby interengagement between the arms and shoulders on the casings whenthe supporting structure was displaced. 7 Y I Disadvantages inherent insuchdevices have to do with uncertainty of spreading o f the anchorarms, and the dif-1 ficulty of causing penetration ofthe arms into thesoil, Similarly, in those devices wherein the arms .are exposed to.lthesoil during driving of the casing, the adherence and compaction of :dirtto the armscon'tribjute to the uncertainty and difficulty of securingdesired'expansion of the anchor assembly.

TTher'present invention obviates these, problems, assuringv positiveexpansion of the anchor assembly, to provide desired footing, andfurthermore contemplates the provision :of readily ,expansible anchorscapable. of ,withstanding-tension or compression loading. Furthermore,by virtue of the essential simplicity of the device, it is readily;possible to construct additional anchorages for" supporting wallsorthelikein'front ofor adjacent to existing construction facilities which are,already'we'ighed' down, sogas toIend' a dditiQnal support to suchfacilities or to. provideadditiohal anchorages for extensionof' suchfacilities.

In accordance with the invention, thereisiprovided an I umbrella anchorassembly including anchor arms carried at the lower endof a shank, whichis movable axially'insidea protective casing and manipulatablef fromthesu'rface above theupper end,of the casing, The arms are positionedcircumferentially:around the shank and pivotally connected to a pair vofcollars in such away that after the casing is removed, onecollar maybe.forcefully moved toward-the other, causing the arms to expand outwardand, away fr'ofn' the shank for engagement with and penetration into theadjacent soil toviform the desired footing., ,To this end,- one.collaris fixed on the end-of the shank andthe other collar .is spacedtherefrom and slidably mounted on the shank for manipulation-fromthesurface by means of a sleeve or tube surrounding the shank. Forcibledisplacement of the sleeve against the movable collar and toward thefixed collar causes posiposition;

'5 5 ofFig. 3;

,Fig. 6 is a view similar to Fig. l showing'a modified- Referring toFigs l'through 5, the expansible anchor sectiongincludin g a 'longitudinally curved base 21 and a'central'web 22, a section of which isdivided into laterally spaced portions 23 resulting in a double-webbed:

. collars to prevent over-expansion of the arms of the anchor. Each ofthe arms carries lateral surfaces 'which face and curve away from theshank, so that when the arms are spread they will move outwardly topenetrate the earth along a path of least resistance, thereby minimizingthe power required to accomphsh anchor expansion. The arms are desirablyformed in T-section'to facilitate direct penetration into the soil, andalso to provide strength and rigidity.

Additional features and objects of the invention, as

, Well as the details of an illustrative embodiment thereof,

will be more fully understood from the following detailed description ofthe accompanying drawings, in which:

Fig. l is a sectional view of the protective casing illustrating thecollapsed condition of the umbrella anchor therein; 7

Fig. 2 is anelevation illustrating the umbrella anchor in opened orspread position after removal of the casing; I

Fig. 3 is an end view of the umbrella anchor in spread Fig. 4 is an endview, partly in section, showing the position of the umbrella anchorin'collapsed condition within the casing;

Fig. 5 is an enlarged sectional view taken on line form of theapparatus; and i Fig. is a view similar to Fig. 2 showing the spreadposition ofthe modified anchoring apparatus.

assembly 10 is mounted on an end portion of anchor shank 11, which isextensible through the cyhndrical protective casing. 12having an openend13 facilitating withdrawal of jthe casing from the'anchor-f'assembly10 throughilheopen end. ,Anchor shank ll'carries' a pair of collars 14and 15,"the former being retained in fixed position onthe' threa ded endof the anchor shank betweennuts 16, .and'thelatter being slidable onshank 1 1 towardQand away frorn collar 14. 'A sleeve 17 is interposedbetween thetwo collars arid mounted on shank 11 to limit the movement ofcollar toward collar 14 for purposesto be explained' A series ofbrackets'ls arefixed on the 'side of collar 14 facing collar 15 forsupporting the ends of anchor arms 19 from hinge connections such aspins 20, the

anchor arms being positioned symmetrically around shank 11 andextendinginthe direction of shank 11 whenin collapsed"con dition as shown in-Fig. 1; Each of the arms '19 is formed to have a'T-shape in'bross Tconstruction as shown in Fig. 3. The base is slotted beneath the.elongated opening 24 formed between web'.

portions 23 to receive a push rod or lever 25; one endof which ishingedbetween web portions 23 and the other end of which' is "hinged*toslidabl'e collar 15, the hinge connections being suitably formedby'pins 26 and 27. J-

The"'base"21of each'bf -the arms comprises a spadelike surface, which isconvex toward shank 11 and which extends from bracket 18 toward the freeend of arm 19 Clos- I 3 with an ever widening lateral dimension, asbetter shown in Flg. 3. The widened outer end 28 of each of the bases issharpened at its forward edge to facilitate penetration into the earth,as will be explained.

In operation, the anchor arm assembly mounted on anchor shank 11 isintroduced into the drill casing 12, which extends into a formationbeneath the earth surface. When in collapsed condition, the anchor armassembly slides freely through the casing, since the arms 19 are mountedby brackets 18 in such a way that the arms pivot inwardly out ofengagement with the inner walls of the casing, forming a clearancetherebetween. After the assembly has been introduced to the bottom ofthe casing, the latter is removed a short distance, as by pulling itupward, so that the anchor arm assembly passes through the end portion13 of the casing and becomes exposed to the earth at the bottom of thedrilled hole. The assembly is then spread open in umbrella-like fashionby forcing collar 15 toward collar 14, as by means of sleeve 29. Thelatter slides over anchor shank 11 into direct engagement with collar 15and is caused to force the latter collar toward collar 14 to open theanchor arm assembly, suitable retaining forces being exerted in anopposite direction on anchor shank 11.

Closing movement of the two collars urges push-levers toward fixedcollar 14 and causes the hinge connection at 26 to force the anchor armsoutward and away from the anchor shank, the arms pivoting about pins 20.Resistance to penetration by arms 19 may be overcome by exertingsufiicient equal and opposite forces on sleeve 29 and anchor shank 11,as by means of a hydraulic press operable at the surface of the earth.Anchor arms 19 are thereby spread open to approach a 90 angle withrespect to shank 11, as shown in Fig. 2, over-spreading of the armsbeing prevented by engagement of collar 15 with the end of sleeve 17. Itwill be apparent that relative displacement between portions of sleeve29 and shank 11 at the earth surface serves to inform the operator ofthe extent and condition of arm spreading.

Once the anchor has been brought into desired spread condition,push-sleeve 29 is removed and casing 12 is pulled upward from the earth,the hollow space left by the'casing then being filled with sand or othermaterial, along with added water, to eliminate any hollow spaces in theearth surrounding the anchor. Alternatively, concrete may be pulled intothe opening to fill the voids'left by removal of the casing.

Forming the bases 21 of the anchor arms to have a convex shape enablestheir penetration into the formation surrounding the anchor with minimumresistance, since enlarging of the penetration openings caused by theirdisplacement into the earth is thereby kept to a minimum. Duringspreading of the arms into the earth, the anchor collar 14 is slightlyshifted inthe direction of pulling upon anchor shank 11; however, afterspreading is completed, further displacement of the anchor is notpossible since the bases 21 of the arms flatly engage a large portion ofthe earth immediately surrounding the anchor, resistance to displacementof which is transmitted to movable collar 15 abutting sleeve 17 andpreventing movement thereof. For this reason, the present device servesvery effectively as a tension-resisting anchor.

In. the construction shown in Figs. 6 and 7, the position of anchor arms19 and push levers'25 is reversed, the arms being hinged to movablecollar 15 and the push levers hinged to the fixed collar 14. Inaddition, the anchor shank 11 comprises end sections 11a and 11bthreaded together in end-to-end relation, and the threaded connection 30between sections 11a and 11b may be rotated to disconnect it fromsection 11a for removal from the drilled hole.

anchor shank spread away therefrom, adapting the anchor assembly to beused as a support capable of withstanding compression loading such asmay be exerted by pilings, columns and the'like. Removal of the casing12 and concreting of the empty hole left thereby remain the same aspreviously described. In addition, it is possible to use a pull cablepermanently fixed to section 11a instead of utilizing anchor shank 11b.

I claim:

1. The combination, comprising an elongated tubular casing adapted to beinserted into a hole drilled underground, an expansible anchor assemblywithin the casing and adapted to be expanded after endwise removal ofthe casing so as to expose the anchor assembly to the surroundingunderground formation, said assembly including an elongated anchor rodaxially movable within the casing to carry said assembly underground andmanipulatable from the surfaceof the earth, a plurality of elongatedanchor arms circularly spaced about the end portion of said rod andextending substantially longitudinally therealong in collapsed conditionaccommodating free axial movement of the entire assembly within thecasing, fixed and movable supports carried in axially spaced relation onthe rod near the end thereof, and means including links and pivotsrelatively loosely interconnecting one end and the intermediate portionof each arm respectively to said supports, each of said arms beingsubstantially longer, than the diameter of said casing and including anelongated relatively narrow blade extending in a longitudinally curvedplane that is everywhere convex toward the anchor rod, each bladediverging from a location adjacent the rod to the free end of the bladeadjacent the inner wall of the casing, the free ends of the blades beingsharpened and having transversely curved relatively widened extent, eachof said arms also including web means integral with said blade andextending longitudinall'y at the blade outer side facing said casing,said pivots being connected to said links, Webs and one of said supportsand said blades containing longitudinally elongated openings throughwhich said links project, and means for displacing saidmovable supportrelatively toward said fixed support for causing the links to swing thearms outwardly about their pivoted ends and away from said rod.

2. The invention as defined in claim 1 in which said supports comprisecollars one of which is attached to the rod near the end thereof and theother of which is axially slidable on the rod.

3-. The invention as defined in claim 2 in which said one end of eacharm is pivotally connected to the collar attached to said rod.

4. The invention as defined in claim 2 in which said one end of each armis pivotally connected to the collar slidable' on the rod.

5. The invention as defined in claim 2' including a stop sleeve on therod between the collars to stop relative closing together movement ofthe collars when said arms have been swung outward to extendsubstantially nor? 1 mal to the rod,and in which said means fordisplacmg the movable collar comprises an elongated sleeve 'on the rodat the side of the movable collar opposite said stop webs and beingpivotally connected thereto.

References Cited in the file of this patent UNITED STATES PATENTS

